Wordnet 3.0
NOUN (1)
1. 
 a unit of information equal to 1024 zebibytes or 2^80 bytes; 
[syn: yottabyte, yobibyte, YB, YiB]
WordNet (r) 3.0 (2006):
YiB
    n 1: a unit of information equal to 1024 zebibytes or 2^80 bytes
         [syn: yottabyte, yobibyte, YB, YiB]